HEADHUNTER92

HEY BILL do u mean its .551 with a 1.7 rocker ? thats .311 cam lobe lift. that means if its a 1.8 he has .560 lift. .009 isnt gonna cause all that to happen. i think its somewhere like i previously posted.

AKlowriderZ71

iTrader: (22)

Headhunter, I think you're looking at MY cam specs, not the OP's cam specs. I have a Trucker cam, he does not. His cam is much bigger.

His cam specs are listed on his build sheet, he posted a pic of it. It says 228/236 duration, .595/.600 lift, 114 LSA +4. These LS engines cam specs are ALWAYS listed as if the engine is using the factory 1.7 ratio rockers. Therefore, the OP's ACTUAL valve lift is .630/.635

Back to the OP's issues. Obviously, the springs weren't able to keep the valvetrain under control. There must have been some serious valve floating going on here. The valves were opening so far that the retainers were beating the **** out of the valve seals. Those are typically the style of seals that are used with dual valve springs. That's my theory anyways, take it for what it's worth.

AKlowriderZ71

iTrader: (22)

This is the other possibility. If the valve lift exceeds this diagrams "measurement B" plus .050", then this valve seal damage can occur. Definately something that needs to be measured, remembering that with the 1.8 rockers, actual valve lift is .630/.635

DrX

iTrader: (7)

Even if it is spec'd for an LS7(1.8 factory ratio)?

budhayes3

iTrader: (19)

That's a good question, I'd think that it would be listed as the lift at the factory spec...

HEADHUNTER92

sure would bill. and most every cam that ive seen sold either had all the specs on the box like elgin does or supplies a cam card with lobe lift specifies due to varying lenghts of rocker ratios available. also.....i went to jim vinci website and didnt see the trucker listed. the one that i did see was called the boss. on the first or second page his post gave the specs of the trucker cam.

HEADHUNTER92

thats were we go back to buying the assembled head thing.most of the time when we assemble heads when a cam is being used .600 lift and above,we install valves with and stem length .100 longer. if the head is designed to be used with .100 longer than factory length(such as world productsdoes) we would then measure and normally it ends up being .100-.150 longer than what they suggest to use.reason, avoid valve seal damage and avoid coil bind that can cause the retainers and keepers to possibly come lose as well. if you can.... assemble one valve put it on the block with two bolts....find a dial indicator set up.....and a valve spring pressure tester(usely made by moroso) and collapse the spring to full compression and see what the dial tells you ur good til.(how far til it bottoms out) or just take it to a machine shop and ask them what the hell is wrong with this damn head. most will do that much for nothing. if your gonna have them fix the issue.

HEADHUNTER92

some machinist even use the small teflon valve seals as well.this allow the top of the guide to be cut alittle lower therefore givin ya more room for lift and clearance. clarence lmao

DrX

iTrader: (7)

Installed a pair of valves and took some measurements.

Intake shims .03"

Spring seats .06"

Installed height to top of spring from top of seat 1.86" (add shims-intake only, and seats as applicable)

Int Lifter travel/lobe lift - .349"
Exh Lifter travel/lobe lift - .355"

Lift at intake valve- .485" Edit- should be .634"


Edit- removed some pics - see post 54 for correct full spring compression pics

Gadgetized

iTrader: (9)

Did you collapse the lifter, or shim under the cup?